Dealing with a sudden leak on my 97 right now too. Started literally overnight. Mine is under the intake it appears. Pulling the intake now to try to find it. I suspect the heater return hose. I rebuilt my engine in December and replaced pretty much everything except the radiator and the coolant hoses under the intake.

#5 is what I'm hoping my problem is. Never been replaced. The one on the 99 has though.